Mark the letter A, B, C, or D on your answer sheet to indicate the cor

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.    

Population growth rates VARY among regions and even among countries within the same region.

• A. A. restrain
• B. B. stay unchanged
• C. C. remain unstable
• D. D. fluctuate

vary = biến đổi
restrain = hạn chế
stay unchanged = không thay đổi
remain unstable = không ổn định
fluctuate = biến động
=> B